System of electric-motor control.



T. VARNEY.

SYSTEM OF ELECTRIC MOTOR CONTROL.

APPLICATION PLED SEPT. 18, 1911.

Patent@ 1111 3, 193.3.

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AORNEY i?. mmm.

l-PLICATIOI TILEB SEPT.1B,1911, r

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'entran sono leo rianne onirica TEODOE VARNLEY, OF PITTSBURGH, PENNSYLVANI, ASSIGNOE T0 WESTINGHQUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPQRATEON GF FENNSYLVa-Nf.

srs'mm or ELECTRIC-Moron' cen'rnon To all whom t may concern.'

Be it known that l, Tirnononn VARNEY, a citizen ci 'the United States, and a resiclent of Pittsburgh, in thecounty of Aillegheny and State of Pennsylvania, have invented a new and useful improvement in Systems of Electric-Motor Control, of which the 'following' is a speci'ication.

My invention relates to systems of electric motor control. and it has special reference to such systems are adapted for electric motor-driven hoists and ore bridges. p

The object of my invention is to provicle a two-motor system oi the class above indicated that shall be relatively simple in ar rangement and particularly reliable in operation.

Special attention has heretofore been direct/tl to the perfecting of single motor control systems for hoist purposes, but systems oit this character are not adapted for use with apparatus having two electric driving motors. Two driving motors are frequently employed,- however, with. large-capacity hoists and ore bridges, and it is my aim to provide a. twomotor system of control that shallr be specially adapted to the service for which it is intended'. v

Figure l of the accompanying drawings is ai diagrammatic .view of a control system 'arranged in accordance with my invention.

Fig. 2 is a simple diagram illustrating the motor circuits and the location of the motor circuit switches.v Figs. 3, l, 5 and G, respectively illustrate the motor-circuit connections for the oli" position, the power or hoist positions, the braking positions antl the kiclcofi1 position.

Referring to l and 2 of the drawings, the. syst-em here shown` comprises switches l to' 17, inclusive, electric motors having armatures 18 and 19 and field magliet'w windings() and 2l, resistors 22, 23', 2%-, llo, and 26, relay switches 27 and 28 and a master'controller 29. The motors are suppliefil with energy from any suitable source through circuit conductors 30 and 3l. The master controller 29 is adapted to occupy-a plurality of power positions c, l), c and d, a plurality of brake positionse, j", g and h,

Specification of Letters Patent.

Application tiled September 18, 1915.. Serial No. tvsl;

an intermediate oil position o and a kiclroft/position ai. Each o" the switches l to l?, inclusive', is rovioleil' with an electromagn-et, anclswitches l0, l1, 15 and 16 arenormal'ly helol closed, being opene by their electro-magnets, while the ren'iainingA switches are normallyi open and are elose by their electro-magnets, when energized. Each of the switches may be provided with a spring vto hold it in its normal position, but, as shownin the drawing, all ofthe switches tend to occupy their open positions by the action of gravity, the switches 10', ll, l5 and 16 being provided with springs which tend to hold them in their closed positions.

rllhe switches l2, 13, le, 15 ancl'l are mechanically interlocled by links 32', 33, 34,

and 35 which cause the switch 16 to open.

larly locked by a link 36 to prevent both of'.-

them rombeing closed at the sainetime, and switches 3 and 1l are interlocked link 37, in like manner.

Assuming that the switches occupy the positions indicatecl'in Fig. l of the drawings, and that the master controller 29 occupies its ofi' position o, the motor circuit connectionsarc as illustrated in Fig. 3 of the drawings. In this position, the motor circuit may be traced as follows: From the ter.- minal 38 of armature 19, 4tlfirough switch l0, conductor 3l) to one terminal of arma tur-e 18, one local circuit being completed through resistor 23, switch 15 and resistor 22, to the opposite terminal of armature 19j another branch being completed from terminal LlO'o armature 1S, through switch 16, resistor 24, field magnet winding` 20, cenductor 41, switch 1l, conductor 42, fielcl magnet Winding 2l, switch l5 and resistor 22.

,45, coilv 46 of switch l2, conductor 47, aux

jliary Contact terminals 48 :of switch 1 and by av terminals (i1, conductor v62, coil 68 of switch conductor 49 to contact-finger 50 of master switch 29. From this point, circuit is completed through contact segments v51 and 52, contact linger 53 and conductor 54 to 'opv posite line conductor 31.' When coil 46 is thus energized, switch 12 is Aclosed and switch 16, which is mechanically interlocked therewith, is opened in opposition to a spring-55. Auxiliary Contact terminals 56 of switch 12 are bridged by the contact member 57 and another circuit is completed from conductor 45, through coil 58 of switch 3, conductor 59, auxiliary contact terminals 56 of'switch 12, conductor 7, etc., as before. Switch 3 is thuselosed and switch-11, which is mechanicallY interlocked therewith, lis opened in opposition to a spring G0. l"Vhen switch 11 is opened, auxiliary contact terminals (l1 are bridged, completing a circuit. from conductor 45 through contact circuit connections are otherwise before-"ttfispossibleV to close the switches 1 and 17 through which energyr is supplied.

As controller 29 .is successively moved into 'position l), oand d', 'the circuit connections remain the same except that resistors 2,5 and 2G are gradually short circuited by reason of in a well known manner, theswitch 8 and 9 being closed .in position th'e switch 6 and v7 in position c and the switches 4 and 5 in position CZ.'

The connection of the motors in parallel for hoisting, as justdescribed and as indicated in Fig.. lain maximum speed with the motors connected directly across the line. lVhen the controller is lmoved into `position c, motor circuit connections are established as shown in Fig. -ofgthe drawings 13, conductor 47, etc., asbefore. The switch 13 is thus closed and the switch 15, which' is mechanicallyy interlocked Atherewitlnis opened. Following the closing of the switch 12, switch 2 is also closed, circuit being completed from conductor L1-5 to coil (34, conductor-h, contact terminals 5G, conductor 417, etc. Switch 10, which is mechanically intel-locked with the switch 2, is accordingly opened. Auxiliary'cmitact terminals' (S6 are bridged when switch 10 is opened and, consequently, current is supplied from conductor 415, through auxiliary contact terminals (S7 of switch 14, conductor (38, contact terminals 6G, conductor 69,' coil 70, of. relay switch 28, conductor 71, Contact terminals 72 of switch' 13, `conductor 73 to contact terminals 74-` of controller.'29,'1"rom this point circuit being completed through con` tact members 7 5 and 52 as before. Thus, it appears that switches 2,3, 12 and 13 and relay switch 28 are closed, while switches 10, 1,1, 15 and 16 are opened. c

-"As soon as relay Switch 28 is closed, the control circuits which were completed through conductor 47 and auxiliaryeontact terminals 11S are completed through -the rela y switch 28 and conductor 54 'to -the line conduetorbl.. rlhey thus become inde' pendent of theA position of 'the switch 1` which is now Closed', circuit being'. completed v:trom conductor ll5 through Contact terminals 67 of switch 11i,y conductor 68, contact terminals 66 of the switch 10, con- (iuotor G9, coil 76, 'contact terminals., 72,. conductor 73, etc. Switch 17'is also closed, circuit being completed from conductor 45, through coil 77, conductor 78, contact ter' minals 79 of switch 3, conductor 80, contact terminal 72, conductor 73, etc. y

llflbtor circuit connections are established as shown in Fig. 4l except that the resistors and 2G are not short. eircuited. Frein the sequence in which the switches are neces-'v and the relayg-switch 28 and theA switch 17 to open. 'lhc f .circuit` connections differ 'from those ot' Fig. in that the switches 1 and 17, through which energy is supplied from the line conductor 30, are opened and' switches 15 and y1G, which'complete circuit yconnections for cach of thc motors, ,are closed. i

As positions f, occupied, the sections of the resistors 25 and 26 are gradually inserted. By this means the operator is able to control the braking laction and' smoothly bring the car or bucket to rest. i f I 1 The motors are shown in Fig. 5, in order to employ the same operation'of one machine as motor and the motor as a generator. 1 l/Vhen it iS necessary-to drive the load "downward, the controller ismoved to positiene, which is commonly known as the nections are establishethj as 'shown4 'in' Fig. 6 of the 'drawings, 11,14 and 17.. Thelme currentis now supthen through theresistor 23, the .motor armatures in'series and vresistor 22 to the opposite side of the circuit.l ltjis evident that the circuit lconnections are so"airan,fred inevery case that the currents traverse the are drivingl the load downward `or are regenerating brakingl current.A This arrangement. has.the?advantageotgavoiding the of the field magnet `poles always, capable of 'building up rapidly-for regenerating thel braking current. f

'Sani-y desean is @vicentina the? noter complete the action of the relay switch 2,7,v

vg and zv vare successively resistance as in hoisting and to preclude. the

plied through the t-wo motor fields in Series,'

field magnet-'windingsin the 'same' direction Whether the motors are hoisting the'load,

losses and delays iii-reversingthepolarity.

and renders them by closingswitches 2,3, 4, 5,'6, 7, 8 and 9,'y and permitting switches 15 and 16 to close connected in 'parallel in l a local circuit for brakmg'purposes, 'as f .110 kick-ott position, in -which circuitcon-:

by'` closing' switches 10, I

` necessary to attain `conductor 94, Enger 95 nece In the kick-oft operation, it is not full speed but it is necessary, or at least desirable, to have :lull-load torque?` The series arrangement shown in Fig. 6 Apermits both motors to develop tullload torque and insures an economic-.il use of power.

The circuitl connections which effect the closingsl of the switches 2 to 9, inclusive, when the controller occupies position c, may be traced es follows: from line conductor 30, through the coil le of relay switch 27, conductor 45 coil 62 of switch 2, conductor 65, Contact terminals 82 oi" switch 16, conductor 83, contact terminalsS-'i of switch'l, conductor 85, contact linger 86 of controller 29, contact segments 87 and 88, Contact tinger 89, and conductor 5st to opposite line conductor 3l.. Another circuit is completed from conductor 45, through coil 5S of switch 3, conductor 59, contact terminals 8'2, conductor 83, etc., as before, Since neither of the switches l and -17 is closed, no energy is supplied to the line and, consequently, the current traversing the coil 44 of the series relay switch 27 is very small. llhe switch 27 is, therefore, closed and, since the switches 2 und 3 are both closed by the energizing of the coils 6i and the switches l0 and 11 which are interloclred therewith, are both opened; A control circuit is, therefore, established from conductor e5, through cont-act terminals 67 of switch lll, which is opened, conductor 68, contact terminals 66 or' switch 10, Contact terminals 90, conductor 91, Contact terminals 92 of switch 9, coil 93, ofcontroller 529 ond contact segments 9 6 and 88 tov linger S9, from which point circuit is completed as before.

Another. control circuit is completed from conductor 91, through contact terminals 97 of switch 8, coil 98 and conductor ..l-l :is hef fore. :immediately tollowingl the closure of switches 8 end 9, holdingcircuits are completed from conductor 4:5, through cont-act terminals 99 and 100, coils (33 und and conductor 9i, as hefore. Control circuits are completed 'from conductor 9L through Contact terminals 10i ot' switch 9, conta 't terminals 102 of switch 7, coil itl-l, condoctor 104i, contact linger l0?) und segments 106 and 88, circuit beinecompleted as he- 'ore A. corresponding control circuit is completed through coil 107, o-F switch (l, and, following the closure of switches and 7, switches l and 5 are similarly closed'` control circuits first heine; completed through conductor 10S and contact linger 109. As the cont-roller 2f? successively occupies positions f, g and fi, Contact fingers '109, liend @l5 are suc sire-ly disengaged from the corcesnmnling;` contact segments of the controller 29 and, consequently, the

"switches Il and 5 orc first 'permitted 'to open, l

the switches G and 7 et the next step and the switches 8 and 9 heine: inally opened to gradually insert the resistors 25 and 2G. Vllhis in accordance with the usuel prectice for hralting cont-rollers.

lll/Then the controller occupies position (c, the circuit connections shown in Fig. 6 are established hy closingr switches i4 and i7, which is eii'ected as follows: Circuit connections are established from line conductor 30', through conductor cl3, coil 44 oit relay switch 27, conductor i5, coil il() or". switch le, conductor lll, linger 112, segments tlS and 114C, Enger and conductor 54- to opposite line conductor 5l. Circuit is also established from conductor 45, through coil 77 of switch 17, concocter 7S, contact terminals 115 of switch 3, which is open, conductor liti to conductor lll., circuit heini; completed as before. Switches Jr and i7 are thus closed and switches 15 and 1G which are int-crlocked with the switches il, are both opened and, consequently, the desired motor circuit connections are established.

lt is evident that modifications in circuit connections may he effected within the spirit und scope of my invention.

l claim as my invention:

l. In control system, the combination with a supply circuit, two motors, und rcsistors, of means tor connecting the motors in independent circuits for operation in one direction, in a, single circuit for operation inv the opposite direction and in independent local circuits for braking.

2. ift hoist 'cm'itrol "ystein comprising e supply circuit, o noir of electric motors, resistors, and means 'for connecting; jthe motors to the supply circuit in multiple relation for hoisting, in series relation Jfor kick-oil and in two local circuits for braking.

3. A. hoist control system comprising4 e .supply circuit, a pair of electric n'iotors, re-

sistors, and ineens for connect-ing the motors to the supply circuit in multiple relation for hoisting, in series relation, with their orinaturc circuits reversed, for 'kick-tui and in two independent local circuits for hrakingr.

hoist control system comprising u. supply circuit, a pair oi electric motors, resistors, and moans for connecting' the vmotors in 'relation in o local circuit when theyv are at rest, for 'xuinoctiugr thc motors to the supply Circuit in multiple relation for hoistius', in series relation 'for kirk-oil and in independent local circuits for braking.

A hoist control system comprising' n supply circuit, n pair ot electric motors, resistors, and means tor connecting 'the motors in series reluliou in u loool circuit when tlny ore at resi, for conuectinglj the motors to the supply circuitl in multiplo relation tor hoistino; and i iruhuiemlcntlocal 'circuits 'for braking.

6. A, hoist control system comprising a supply circuit, a pair of electric sisors, and means for connecting; the motors in series leuion in L local Circuit when they are at rest, to the supply ircuit in multiple felation for hoisting and i series relation for kick-0H.

In testimony whereofy I have hereun for connestng the motors l motors, rte-n ,Subscribedl my name his 2th day ofi Sept,

TfmODOR-E VARNEY.

Wtnesse: I D. 3H. MACE, B. B, EINES. 

